1. Field of the Invention
The present invention relates to an apparatus, in particular for positioning and fastening a device, in particular a handle on a power tool.
2. Description of the Prior Art
One such apparatus is known from German Patent Application DE 10 2008 000 158 A1, which was not published prior to the filing date of the present application. The known apparatus has a handle, with a clamping ring which is fastened to the handle and on the inside circumference of which longitudinal ribs are formed that cooperate with corresponding complementary geometries on a power tool. The clamping ring is movable on the handle by means of a tension lever between a first position, in which the power tool can be put into operative connection with the clamping ring, and the second position for fixation of the clamping ring on the power tool. By means of the known apparatus, the handle can be fixed in various radial positions relative to the power tool.
A handle of this kind is typically used in power tools, such as an electric power drill or the like, to make it possible to hold the power tool with both hands on different handles. A further embodiment is shown in German Utility Model DE 79 27 713.7 U1, from which a supplementary handle for an impact drill is known that includes a grip and a clamping ring. The grip is fastened to the clamping ring by means of a screw element, and the clamping ring is embodied in open fashion and has two tabs on which a ring screw is provided. The clamping ring can be clamped or unclamped by tightening or loosening the wing screw. However, such an embodiment has many different parts, and the clamping requires an undesirable screwing operation.
From German Patent Disclosure DE 41 32 058 A1, a supplementary handle for a power drill or the like is also known, in which the clamping ring again has two tabs, through which one long screw is passed. This long screw likewise serves the purpose of fixation of a grip, and clamping or release of the clamping ring is attained by rotation on the grip. Although the number of parts is reduced in this embodiment, nevertheless it can in particular happen that in heavy-duty use of the power tool, the grip is unintentionally rotated, causing the clamping ring to come loose from the power tool. This can result in dangerous situations for a user of the handle.